High-quality Salt Bath Nitride Bolt carrier group used in a majority of the Franklin Armory complete firearm builds.  Works very well with the Franklin Armory binary triggers. Technical Specifications Carrier machined from 8620 Steel Bolt machined from Carpenter No. 158 steel MPI Bolt M16 full auto style Properly staked gas key Polished finish Franklin Armory logo included Treated with SBN (Salt Bath Nitride) Bolt Machined from 9310 or 158 Carpenter steel (depending on availability) Extractor "O-Ring" Extractor “Spring” Stainless Steel Firing Pin